remove unused dimension value

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

src/main/res/values/dims.xml

@@ -18,7 +18,6 @@
 <resources>
     <!-- Default screen margins, per the Android Design guidelines. -->
     <dimen name="nav_drawer_header_height">164dp</dimen>
-    <dimen name="nav_drawer_header_avatar_radius">28dp</dimen>
     <dimen name="nav_drawer_menu_avatar_radius">12sp</dimen>
     <dimen name="list_item_avatar_icon_radius">20dp</dimen>
     <dimen name="bottom_sheet_menu_item_divider_standard_margin">56dp</dimen>